Variable Pitch Perforation Line for Corrugated Packaging
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Solution Overview
Problem
Existing corrugated cardboard packaging with perforation lines for easy opening suffers from reduced stability, leading to unintentional opening during transport, storage, or handling, and requires additional material and resources to enhance strength.
Innovation Solution
A perforation line designed as a closed, arc-shaped line with variable material gaps and bridges that run parallel to the corrugation orientation in some areas and deviate in others, providing high stacking crush resistance and easy opening without tools, suitable for double- or multi-walled cardboard.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a perforation line is provided as an opening aid, then ease of opening is improved, but stability and stacking crush resistance deteriorate
Solution Approach 1:
The patent applies different properties to different parts of the perforation line. Material gaps are created at specific locations where opening force is applied, while material bridges maintain structural integrity in other areas. The angle of attack varies locally along the perforation line, with sharper angles at material gaps for easy tearing and gentler angles at material bridges for maintaining strength.
Solution Approach 2:
The perforation line is segmented into alternating material gaps and material bridges. This segmentation allows the opening aid to be torn at specific points (material gaps) while maintaining structural continuity through the material bridges, resolving the contradiction between ease of opening and overall stability.
2Strength
If wall thickness or material quality is increased to prevent unintentional opening, then stability is improved, but material consumption and costs increase
Solution Approach 1:
Instead of uniformly increasing wall thickness or material quality throughout the packaging, the patent locally modifies the perforation line structure with material gaps and bridges. This allows the packaging to maintain adequate stability without requiring additional material or thicker walls, thus avoiding increased material consumption and costs.
3Ease of operation
If the perforation line is made to tear easily, then ease of opening is improved, but stacking crush resistance deteriorates
Solution Approach 1:
The patent changes the geometric parameters of the perforation line, specifically the angle of attack of material gaps and bridges relative to the corrugation direction. By optimizing these angles, the packaging achieves both easy tearing at material gaps and adequate stacking crush resistance through material bridges with more favorable orientation.
Solution Approach 2:
The perforation line is divided into segments with different functions: material gaps optimized for easy tearing and material bridges optimized for maintaining structural strength. This segmentation allows each part to be optimized for its specific function without compromising the other.
Data Source
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AI summary
The aid has a perforation line (2) with material straps (4), material gaps (3) and curved-in sections, where the material straps and/or material gaps have an alignment differing from tangent to the perforation line with a setting angle changing over characteristics of the perforation line. The setting angle is selected such that force vector acting on the material gap when breaking the aid forms an angle between the material gap and force vector of 75 to 105 degrees.